Airbags are generally used in vehicles to protect the occupant during an accident and to prevent severe injuries wherever possible. Said airbags are located in different components or vehicle parts and are abruptly inflated at an early stage of the accident, so that they cover the components or the vehicle parts and protect the occupant or the pedestrian against directly hitting certain surfaces of the vehicle interior.
An airbag which is of particular importance for the protection of the occupant is the curtain airbag which is attached above or below the side window structure of the vehicle and, when being inflated, deploys in such a way that in the inflated state it forms a cushion which is located on the side of the head of the occupant. First of all, the curtain airbag prevents the occupant from hitting the side vehicle structure or the side window surfaces with the head or the upper part of the body during an accident owing to the occurring lateral accelerations, and, secondly, it prevents the occupant from being catapulted through an open window out of the vehicle interior to the outside with the head or the upper part of the body. In closed vehicles, the curtain airbag preferably unfolds downwards in a curtain-like manner out of the vehicle structure which delimits the windows at the top side. In cabriolets, the curtain airbag preferably unfolds upwards out of the upper edge of the door. Due to its function, the curtain airbag has a very large surface and, depending on the vehicle type, extends from the A-pillar to the rear C- or D-pillar and thus can have a length of up to 2 to 3 meters. Furthermore, the curtain airbag must cover preferably the whole surface of the vehicle structure located on the side of the upper part of the body and of the head, so that at least in sections it must have a height of 40 to 100 cm. The curtain airbag thus has a very large surface and generally is the largest airbag to be provided in the vehicle.
In order that the curtain airbag, despite its length and its surface, in the inflated state has the required form stability and thereby prevents the occupant from being catapulted out of the vehicle interior, the curtain airbag is fastened to the A- and C- or D-pillar of the vehicle structure preferably in the longitudinal direction of the vehicle using additional tightening straps.